Continuous rayon spinning and processing machine



y 1936- P. E. HARRISON 2,041,333

CONTINUOUS RAYON SPINNING AND PROCESSING MACHINE Filed Aug. 8, 1934INVENTOR.

ATTORNEY.

having improved characteristics. Another object of my inventiohis toproduce a satisfactory rayon Patented May 19, 1936 PATENT OFFICECONTINUOUS RAYON SPINNING AND PROCESSDIG Paul E. Harrison, Dover, N. B.

Application August .8, 1934, Serial No. 738,906

7 Claims.

This invention relates to the manufacture of rayon. More particularlythe invention relates to a continuous method of manufacturing rayon. Theinvention has particular applicability to the viscose process ofmanufacturing rayon and it will be described in connection with thatprocess. It is to -be understood, however, that that descriptionvisexemplary, not limitative.

Heretofore the manufacture of rayon by the viscose process has beencarried out by extruding a viscose solution into a regenerating (withinwhich term is included both coagulation and regeneration) bath,withdrawing it from the bath in theform of. a continuous thread,collecting the threadinthe form of an annulus on the surface of a bobblnor within a centrifugal bucket, and s jecting; the annulus to washing,desulfuring, bleachlng, and to theother processes which serve in theproduction of thread of good quality. After the liquid treatment of thethread annulus has been completedfthdthread is dried, unwound, and isrewoundin packages which are sold to manufacturersof cloth.

The prior art methods of manufacturing viscose rayon have several gravedisadvantages, not the least of which the tendency of regeneratedcellulose threzidfwhen dried in a cake or on a bobbin, toshrinlrunevenly and form a thread of non-uniform denier. Variousmethods: have been invented to eliminate this defect of the prior artprocesses but, while some of them have produced a'thread having a moreuniform denier,

.each of theni hasinvolved the'addltlc'n'i of a step to the prodssghaveincreased the cost of the process, and have failed to eliminate fullythe disadvantages.

'.It is an object of my invention to produce a thread of rayon andparticularly of viscose rayon,

thread by new process. Another object of the invention is to overcomedisadvantages inherent in older processes. Yet another object of theinvention is to produce an apparatus capable of eificlently contributingto the practice of the new process. Other objects of the invention willhe in part apparent and 'in part hereinafter set forth.

The objects of the invention are accomplished, broadly speaking, byforming a gelregenerated cellulose thread by any approved process of theprior art but preferably by regeneration in a bath containingregenerating liquid, withdrawing the thread from the bath, supporting itupon the surface of a moving support which is preferably permeable toliquids, successively treating it, while thus supported, with thematerials and reagents which contribute to its proper formation. dryingthe thread, twisting it, and gathering it in a convenlentforrn. Theobjects of the invention are also accomplished in a greater or lessdegree by the details of process and the details of apparatushereinafter more fully described.

In the drawing, which diagrammatically illustrates a preferred form ofmy invention, Figure l is a diagrammatic side view of an apparatusembodying my invention. Figure 2 is a plan view, with the upper rollersremoved, of the apparatus shown in Figure 1.

Referring to the numerals in the drawing, H) are filters of a type knownto the prior art through which a viscose solution passes before beingextruded into a regenerating medium; II are spinnerets of a type knownto the prior art through which a thread is extruded in the form of asingle filament,"or in the form of a plurality of filaments; I2 is 'atank; (3 is a regenerating liquid contained inthe tank; I, Mi, H2, H3are threads; 202I are pressure rollers which serve to draw the threadfrom the regenerating bath at a rate which permits its substantiallycomplete regeneration, and which exert only enough pressure to expelfrom the thread liquid carried with it from the said bath,and not enoughto damage the filaments; 22 is a pipe which extends across the machine;13, 23L 232',- 233 are nozzles located in a position such. that fluidforced through them will bathe the thread as it is drawn through themachine; 24 is a. pan-'beneath the shower and thread to collect theliquid with which the thread is bathed; 80 is an endless belt,preferably made of liquid-permeable fabric, which is carried and movedby the lower rollers to support the thread and to carry the threadthrough the varioussteps of the process; 801 is an endless belt carriedabout the upper series of rollers; 30-3| are pressure rollers of' whichroller 30 is of smaller size than roller 31; 1 is a trough forcollecting fiuid expressed from the belt and thread between pressurerollers 30-31; 33 is a pipe capable of carrying fluid; 3 i-34i 342-343are nozzles through which fiuid from the pipe 33 may be directed uponthe thread; 35 is a trough or pan to collect used liquid; fill-41ampressure rollers; 42 is a trough to collect liquid; 43 is a pip 444l-2263 are nozzles to direct the liquid in pipe 43 upon the upper belt ata point just above the thread; 45 is a drip trough; -5 ar pressurerollers; S'Zis a drip trough; 53 is a pipe to contain fluid; St-SiL-Stf-JU are nozzles to direct fluid from the pipe 53 under thethread; 55 is a drip tank to collect used fluid; Gil-Bi are pressurerollers; 62 is a drip trough; G3 are pipes to contain drying fluid, suchas warm air; 64642543 are nozzles to direct the drying fluid against thethreads; 10-H are pressure rollers; 80 is a guide roller; 8| is atwisting and collecting means, in this instance illustrated as acentrifugal bucket; 82 is a reciprocable guide which serves to lay thethread in successive helices against the interior of the centrifugalbucket.

The apparatus in a preferred form of the invention functions as follows:The viscose, or other regenerable cellulose solution, is ejected intothe regenerating bath, which usually contains sulfuric acid as theregenerating medium. The thread is formed by the regeneration of theviscose solution in the form of a plurality of continuous filaments, andis drawn between the protecting belts and the pressure rollers 20 2l.The belts are driven at a rate which permits the substantially completeregeneration of the thread during its travel in the regenerating bath.The belts carried by the upper and lower series oi rollers arepreferably fabric belts having an open weave which permits liquids topass readily through them but which serve to support the thread, tocarry it through the apparatus, and to protect it against damage fromthe force of the showers. As the thread leaves the rollers 20 2l,carried upon the surface of the belt 80, it passes beneath shower 23(or, if advisable, a. series of showers) which is preferably of water inorder to remove the regenerating fluid. The fluid from the nozzle washesthe regenerating fluid from the thread and the majority of it passesthrough the fabric and is caught in the receiver 24 and is returned tobe used again or to be regenerated. Of course, a regenerating fluidshower could be inserted before the washing shower if regenera tion werenot completed in the bath.

The thread as it leaves the shower contains a considerable quantity ofwater which would dilute the next solution. However, the pressurerollers till-3i, which are driven, expel from the thread and from thebelts liquid which would otherwise dilute the treating. solution in thenext step. Much of this liquid is carried down the surface of roller 30and is collected in the receiver 32. The rollers 30405fl60 are ofsmaller size than the end rollers 20'|0 in order to permit thecollection of the expelled liquid. These smaller rollers 3ll40-50-60 aredriven at the same peripheral speed as 'their companion rollers3i--4|-5l5|.

Having lost excess water between the pressure rollers the thread iscarried by the belt and the rollers to a position beneath the nextnozzle, which showers it with a desulfuring solution. This solutiondesulfurs by reacting with the material of the thread to free sulfur andthen washes the freed sulfur out of the thread, a function which is butpoorly performed by the immt ion bath typical of the prior art. In thisstep of the process a certain amount of shrinkage occurs in the thread,but the rollers 303l, ill-4| grip the thread with even tension andpropel it with uniform speed, so that each portion of the thread issubjected to uniform shrinkage for a period 0 time equal t'l that ofevery other portion. This is a great improvement over the prior art,wherein all shrinkage took place against opposition which variedaccording to the thickness of the windings beneath it.

In order that the shrinkage of the thread shall be uniform in this stepof the process, it is de sirable that a uniform viscose solution shallbe sent through the spinneret into the coagulating bath, and that theregenerating bath or baths and the desulfuring solution shall each be ofuniform concentration and content.

Excess desulfuring solution is squeezed out of the thread and belt bythe rollers and the thread is carried on to be treated in a similarmanner with other necessary and desirable fluids. In the drawing therehave been illustrated in separate steps washing, bleaching, and drying.In addition to these steps a washing step could follow the bleachingstep, a soaping step follow the washing step, a washing step follow thesoaping step. a dyeing step follow the washing step, and a washing anddrying step follow in order. It will be understood by persons skilled inthe art that any treatment which has heretofore been carried out inanimmersion or batch process can be carried out by my invention and thatthe order of treat ment need not be altered.

In the drying step wherein the greatest shrinkage occurs particular careshould be taken that the temperature of the air which is blown throughthe nozzle 64 is constant, that the moisture content of that air shallbe controlled closely, and that each portion of the thread shall beexposed to the heated air for equal periods of time.

After the drying the thread is twisted and collected in a package. Ihave illustrated in the drawing a centrifugal bucket and customaryreciprocating mechanism to accomplish this function. It is not necessaryto use this bucket, however, for any standard method of twisting andpackaging can be used. For instance, the thread can be collected onbobbins with twisting or it can be twisted and collected on a capspinner. When removed from the collecting device the thread is ready forsale. On the other hand, if the manufacture of staple rayon is intendedthe twisting and collecting step will be omitted, the thread will be runwithout twisting to a chopping machine which will cut it in the lengthssatis factory for use in spinning threads.

No driving mechanism has been illustrated because such mechanisms arewell known and widely used, are many in number, and are of approximatelyequal efficiency. Suffice it to say of the driving that it is desirablethat all rollers shall have the same peripheral speed. This can beobtained by driving both sets of rollers, or by mounting the upperrollers freely to be driven by friction from the lower rollers.

The manufacturing apparatus can be made of size sufficient to take onlyone thread or it can be made of size sufficient to take a large numberof threads. In actual practice in my invention the spinnerets would bespaced close together.

In the drawing the means for collecting and draining the used liquids isdisclosed as a very simple one. Other methods will occur to personsskilled in the art.

The upper belt may be omitted under certain circumstances but generallyits use is preferred. That modification of the invention which omits theuse of any belt is not recommended for general purposes.

An advantage of this invention is in the production of thread morehighly uniform than thread heretofore known. Another advantage of theinvention is in an improved and simplified process of producing aregenerated cellulose thread. Another advantage of the process is in anapparatus which lends itself to the eflicient working of the new processand to the production of the ne product.

Many changes may be made in my process and apparatus, but such changesas fall within the claims are mere expedients within the ability of anymechanic.

I claim:

1. An apparatus for manufacturing rayon thread comprising means forregenerating a viscose solution in the form of a thread, means fortwisting and collecting the dried thread, a series of nozzles betweenthe regenerating means and the collecting means, means for transportingthe thread from the regenerating means to the collecting means beneaththe said series of nozzles and for protecting the thread from the forceof the showers comprising a pair of movable, liquid-permeable, endlessbelts between which the thread is carried, means to supply to eachnozzle of the series a separate fluid whereby the thread may besuccessively bathed by processing liquids, pressure rollers betweenadjacent nozzles to expel excess liquid from the thread and belt, meansto collect the liquid which passes through the belt and means to collectliquid expelled by the rollers.

2. An apparatus for manufacturing rayon thread comprising means forregenerating a viscose solution in the form of a thread, means fortwisting and collecting the dried thread, a series of nozzles betweenthe regenerating means and the collecting means, means for transportingthe thread from the regenerating means to the collecting means beneaththe said series of nozzles comprising a pair of movable,liquidpermeable, endless belts between which the thread is carried,pressure means between adjacent nozzles to expel excess liquid from thethread and belt, and means to collect the used processing liquids.

3. An apparatus for manufacturing rayon thread comprising means forregenerating a viscose solution in the form of a thread, means fortwisting and collecting the dried thread, means between the regeneratingmeans and the collecting means to successively bathe the thread invarious processing fluids, means for transporting the thread through thesaid baths comprising a plurality of permeable webs between which thethread is carried, pressure means between successive baths to expelexcess fluid from the thread, and means to collect the used processingfluid. I

4. The method oi! making viscose rayon which comprises drawingregenerated thread from a re- 5 generating bath without deviation to thewindup, spraying the thread with washing, desulfuring, and dryingfluids, maintaining the temperature, concentration and constitution ofeach bath constant throughout the process, protecting the thread fromthe force of the baths, maintaining uniform temperature, flow, andhumidity of the drying medium, and substantially preventing lengthwisecontraction of the thread during any step of the process. 15

5. The method of making viscose .rayon which comprises drawingregenerated thread from a regenerating bath without deviation to thewindup, spraying the thread with washing, desulfuring, .and dryingfluids, maintaining the temperature, concentration and constitution ofeach bath constant throughout the process, protecting the thread fromthe force of the baths, maintaining uniform temperature, flow, andhumidity of the drying medium, and substantially preventing 25lengthwise contraction of the thread during desulfuring and drying.

6. In the method of manufacturing rayon thread which includes forming aregenerated cellulose thread from viscose and drawing it suc- 30cessively through baths of water, desulfuring fluid, water, bleachingfluid, water, dyeing fluid, water, and a current of. hot air, the stepswhich comprise drawing the thread without deviation through the steps ofthe process, and pressing the 36 thread gently with sets of rollerslocated between steps whereby to expel absorbed liquids therefrom and tooppose shortening by shrinking.

7. In the continuous method of manufacturing rayon wherein the thread isdrawn from a regenerating bath and passed through successive processingsteps, the steps which comprise moving the thread without deviationthrough the baths of the process between moving permeable fabric 46belts, and by gripping and pressing the thread between steps to expressliquid therefrom, prevent longitudinal contraction thereof, and applytension thereto.

PAUL E. HARRISON. 5o

